1. Field of the Invention
The present invention relates to an information processing apparatus, a power mode control method, and a power mode control program product.
2. Description of the Related Art
In recent years and continuing, network devices are required to consume less power from the viewpoint of reducing emissions of carbon dioxide which causes global warming, and reducing cost with minimizing power consumption. Under such circumstances, for the purpose of reducing power consumption, network devices (devices in a network) such as information processing apparatuses and image processing apparatuses with the following function are being proposed. That is, network devices with a power saving mode (also referred to as energy saving mode or sleep mode) are proposed, to maintain the device in a low-power consumption state as long as possible. In a network device having an energy saving function, when there are no instructions to operate for a certain period of time, power consumption is reduced by switching to a sub-CPU which consumes less power, from the main-CPU which is used in a regular power mode.
In recent years and continuing, networks are becoming increasingly complex, and various network-compatible devices are connected to the network. Devices with an OS (Operating System) such as Windows (registered trademark) perform packet communications on a regular basis, and transmit predetermined packets on a regular basis. Accordingly, a network device needs to frequently receive packets that are regularly transmitted by the OS and to transmit packets that are regularly requested by the OS. For this reason, it is becoming increasingly difficult to maintain the power saving mode where power consumption is low.
In the device disclosed in patent document 1, it is possible to set the conditions for returning to a regular power mode from the energy saving mode. Accordingly, when a particular packet is received, the network device can return to the regular power mode from the energy saving mode. In an actual network environment, the network device frequently receives search packets from search applications and search packets from Windows (registered trademark). These packets are processed in the regular power mode. However, in the power saving mode, these packets are deemed as ineffective (i.e., unnecessary and therefore do not need to be processed). Accordingly, power consumption can be reduced by maintaining the power saving mode as long as possible. When the device disclosed in patent document 1 is in a power saving mode, it does not return to the regular power mode when the above packets are received, and continues to maintain the power saving mode. Accordingly, power consumption is reduced by maintaining the energy saving mode as long as possible.
Patent Document 1: Japanese Laid-Open Patent Application No. 2006-309731
In the invention disclosed in patent document 1, packets that are processed in the regular power mode are ineffective (unnecessary) in the power saving mode, so that a power saving mode can be maintained as long as possible. However, as described above, in recent years and continuing, the network is becoming increasingly complex and network devices need to frequently respond to requests for processing packets from the network. Therefore, even if the network device had a power saving mode function, it would be difficult to switch to the power saving mode. Accordingly, the network device is in an environment where the function of the power saving mode cannot be fully put into practice. That is, there is a need for a network device supporting plural network protocols to smoothly switch to the power saving mode from the regular power mode. This is also a problem which needs to be addressed for the purpose of saving energy.